It is not rare for snow to fall along the Colorado Front Range during the month of May. An unruly spring jet stream, significant changes in elevation and the presence of a storm system crossing the Desert Southwest are the usual ingredients.
The current snow storm, which began yesterday, developed as a deep atmospheric trough (dip in the jet stream) allowed cold, Canadian air to drop southward along the Front Range while counterclockwise winds, around a low pressure center in New Mexico, pulled in Gulf of Mexico moisture from the Great Plains. This upslope flow dropped two feet of snow in the mountains, a foot of snow in the foothills and rain changing to snow along the Front Range urban corridor.
This welcome moisture will likely have a limited effect on the State's drought and on Metro Denver's water shortage but it is surely welcomed by the regional flora and fauna. Perhaps the greatest benefit of the storm will be to diminish the threat a wildfires across the eastern slope of the Front Range as the annual fire season gets underway. Early and prolonged Southwest Monsoons and normal to heavy mountain snowpacks over the coming years are needed to end the drought.
